This invention relates to open structure, net-like composite filaments and in particular to composite filaments comprising intersecting wavy filaments having a rotational component, e.g., spiral or helical, and joined to one another at a majority of their intersecting points.
Commercially available fibers, filaments and yarns are made of natural and synthetic materials which are generally solid in cross-section. In the past these materials have been designed for long wear in garment construction and for scuff and abrasion resistance in carpets and other floor coverings. Present day architectural and design practices often call for interior and exterior surface coverings, other than for floors or decks made of woven, non-woven or flocked fibrous materials. Such surface coverings require inexpensive fibers and filaments and are characterized by exceptionally high bulk/weight factors combined with excellent thermal, sound and electrical insulating properties. The use of conventional fibers and filaments in these applications is expensive, however, because of the unfavorable bulk/weight factors.
The present invention provides composite filaments which are characterized by an open, net-like structure, which greatly increases their space-filling bulk per unit weight and provides inexpensive and material saving filaments. The open structure of the composite filaments of the invention greatly improve thermal, electrical and sould insulating properties and can be used in the fabrication of non-woven, woven, knitted, and flocked materials and articles in much the same way as solid fibers and filaments. The composite filaments of the invention provide an excellent appearance at greatly reduced cost from a materials standpoint and greatly reduced weight per unit area.